Re: [tip:x86/boot] x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G

[Ingo Molnar <mingo@kernel.org>]

* Kirill A. Shutemov <kirill@shutemov.name> wrote:

> On Tue, Feb 13, 2018 at 12:41:22AM -0800, Andrei Vagin wrote:
> > On Tue, Feb 13, 2018 at 11:08:16AM +0300, Kirill A. Shutemov wrote:
> > > On Mon, Feb 12, 2018 at 10:51:56PM -0800, Andrei Vagin wrote:
> > > > Hi Kirill,
> > > > 
> > > > Something is wrong in this patch.
> 
> Could you please check if this makes a difference?
> 
> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index 70b30f2bc9e0..99a0e7993252 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -332,7 +332,7 @@ ENTRY(startup_64)
>  
>  	/* Make sure we have GDT with 32-bit code segment */
>  	leaq	gdt(%rip), %rax
> -	movl	%eax, gdt64+2(%rip)
> +	movq	%rax, gdt64+2(%rip)
>  	lgdt	gdt64(%rip)

There's another suspicious looking pattern as well:

        leaq    startup_32(%rip), %rax
        movl    %eax, BP_code32_start(%rsi)
...
        movl    BP_code32_start(%esi), %eax
        leaq    startup_64(%rax), %rax
...


Thanks,

	Ingo